#!/usr/bin/env bash
set -ex

# docker_shell — unified launcher for AutoTuner / OpenROAD
#
# Usage: etc/docker_shell [OPTIONS] [-- CMD [ARGS...]]
#
# Options:
#   -i, --image IMAGE Docker image (overrides $OR_IMAGE and default)
#   --user            Map host UID/GID into the container via entrypoint.sh
#   -p, --port SPEC   Forward a port, e.g. --port 8265:8265 (repeatable)
#   --dry-run         Print the docker command without executing it
#   -h|--help         Show this help and exit

#
# Method to use docker CLI to determine if we're using docker or podman
#
# Sets container_engine global variable with either "docker" or "podman"
#
get_container_engine () {
    local DOCKER_VERSION_STRING=$(docker --version 2> /dev/null)

    if [[ "$DOCKER_VERSION_STRING" == *"Docker"* ]]; then
        container_engine="docker"
    elif [[ "$DOCKER_VERSION_STRING" == *"podman"* ]]; then
        container_engine="podman"
    else
        echo "Unable to determine container engine using docker CLI"
        exit 1
    fi
}

DEFAULT_IMAGE="openroad/orfs:latest"
FLOW_DIR="/OpenROAD-flow-scripts/flow"
USE_USER=false
DRY_RUN=false
PORTS=()
IMAGE=""
CMD_ARGS=()

usage() {
    grep '^#' "$0" | sed 's/^# \{0,1\}//'
    exit 0
}

while [[ $# -gt 0 ]]; do
    case "$1" in
        -i|--image)  IMAGE="$2"; shift 2 ;;
        --user)      USE_USER=true; shift ;;
        -p|--port)   PORTS+=("$2"); shift 2 ;;
        --dry-run)   DRY_RUN=true; shift ;;
        -h|--help)   usage ;;
        --)          shift; CMD_ARGS=("$@"); break ;;
        -*)          echo "Unknown option: $1" >&2; exit 1 ;;
        *)           CMD_ARGS=("$@"); break ;;
    esac
done

# Image resolution: --image > $OR_IMAGE > default
IMAGE="${IMAGE:-${OR_IMAGE:-$DEFAULT_IMAGE}}"

get_container_engine

WORKSPACE=$(pwd)
YOSYS_EXE=${YOSYS_EXE:-/OpenROAD-flow-scripts/tools/install/yosys/bin/yosys}
OPENROAD_EXE=${OPENROAD_EXE:-/OpenROAD-flow-scripts/tools/install/OpenROAD/bin/openroad}
KLAYOUT_CMD=${KLAYOUT_CMD:-/usr/bin/klayout}

XSOCK=/tmp/.X11-unix
XAUTH=/tmp/.docker.xauth
if ! $DRY_RUN; then
    xauth nlist ${DISPLAY:-:0} | sed -e 's/^..../ffff/' | xauth -f $XAUTH nmerge -
fi

if test -t 0; then
    DOCKER_INTERACTIVE=-ti
else
    DOCKER_INTERACTIVE=
fi

if $USE_USER; then
    user_args="--entrypoint=entrypoint.sh --user=root"
    user_env="-e CUSTOM_USER=$(id --user --name) -e CUSTOM_USER_ID=$(id --user) -e CUSTOM_GROUP_ID=$(id --group)"
elif [[ $container_engine == "podman" ]]; then
    user_args="--privileged --userns=keep-id --user $(id -u):$(id -g)"
    user_env=
else
    user_args="-u $(id -u ${USER}):$(id -g ${USER})"
    user_env=
fi

PORT_ARGS=()
for port in "${PORTS[@]}"; do
    PORT_ARGS+=(-p "$port")
done

CMD_STR=
[[ ${#CMD_ARGS[@]} -gt 0 ]] && CMD_STR="${CMD_ARGS[*]}"

ENV_SH_CMD='if [ -f ../env.sh ]; then . ../env.sh; fi;'

# Build the command once; dry-run prints it, otherwise exec it.
DOCKER_CMD=(
    "$container_engine" run --rm -i
    $DOCKER_INTERACTIVE
    $user_env $user_args
    -e LIBGL_ALWAYS_SOFTWARE=1
    -e QT_X11_NO_MITSHM=1
    -e XDG_RUNTIME_DIR=/tmp/xdg-run
    -e "DISPLAY=${DISPLAY:-:0}"
    -e QT_XKB_CONFIG_ROOT=/usr/share/X11/xkb
    -v "$XSOCK:$XSOCK"
    -v "$XAUTH:$XAUTH"
    -e "XAUTHORITY=$XAUTH"
    -e FLOW_HOME=/OpenROAD-flow-scripts/flow/
    -e WORK_HOME=/work
    -e "YOSYS_EXE=$YOSYS_EXE"
    -e "OPENROAD_EXE=$OPENROAD_EXE"
    -e "KLAYOUT_CMD=$KLAYOUT_CMD"
    -v "$WORKSPACE:/work:Z"
    --network host
    "${PORT_ARGS[@]}"
    "$IMAGE"
    bash -c "set -ex; mkdir /tmp/xdg-run; cd ${FLOW_DIR}; ${ENV_SH_CMD}$CMD_STR"
)

if $DRY_RUN; then
    echo "${DOCKER_CMD[*]}"
    exit 0
fi

exec "${DOCKER_CMD[@]}"